"The biggest thing is the quality of the stainless inside the grill. Bring a magnet with you to the store . If it sticks, it is a lower quality steel. (430 grade vs 304) 304 is better.

With regard to the brands, I have been out of the loop for a full year now. In the past, this was the low down:

Broil King - 430 grade. Average life is 10 years. Within the 10 years, you will replace the sear plates (and possibly burners) 2 to 3 times.

Vt Castings - Exact same life expectancy as BK, but a much better grilling experience. Temperatures across the grill surface will be the most even you will find in this price range.

Napoleon - 304 interior parts. (Prestige line only). 10 to 15 year life expectancy but you won't be replacing parts. Mine is 12 years old with the original burners & plates. Burners are still awesome, but the plates are done. Not as even heat as Vt. Avoid Napoleon's built in China. They are awful.

Weber - I would only buy the Genesis. Spirit seemed to have cheaper build quality, and Summit (IMO) is over priced. Out of all of these brands, probably the best build quality. Just have to watch the type of interior stainless. Weber is famous for changing this depending on the retailer. FYI - If you do a lot of bbq in the dead of winter, it may not get hot enough. Same life expectancy as the Napoleon.

Your results may vary where you are, but this is our experience here in Ontario."

Everyone will have their own opinions of course, but this is what I learned working 11 years working at a fireplace shop that sold $200,000 to $300,000 BBQ's/year.

It will be almost impossible to find a grill that is 100% North American. All of them have at least some parts sourced in China. Crown Verity will be the closest you will get. The plastic knobs & wheels are the only off-shore parts.

First, unlike most electronics, there is a legitimate "build quality" factor that you really just can't evaluate without being able to touch the thing. I had a hard time - even in the Seattle metro area - putting my hands on many of the models I was interested in.

Second, there are design nuances that - likewise - you can't really ascertain easily solely from web resources. The drip-pan and bottom of the Genesis firebox have been completely redesigned compared to my older model. And they really put some thought into not only how it would perform, but also how much work I'd have to do to maintain it. I looked at a Kitchenaid brand grill at Costco; it was lovely, but the drip pan wasn't removable, and was very close to the burner bars. So, I passed.

Edit: One other thing... Weber makes "premium" versions of the Genesis models that have the enamel (rather than stainless) lid. The E-310 has enameled-cast-iron grates and burner bars but the EP-310 has stainless interior components.

If anyone is in the market for a top end, hand made in the USA grill that will last a lifetime, take a look at Kalamazoo. Frightfully expensive, but if I were planning to build an outdoor kitchen, or kickass patio, I'd give them serious consideration.